Holocene raised bog deposits in the Netherlands as geochemical archives of prehistoric aerosols

High resolution records of lead and some other elements in Holocene raised bog deposits from the eastern Netherlands were compared with corresponding pollen records for the period 1000 bc to ad 1000. Trends in the curves of herbaceous human influence indicators parallel the recorded fluctuations of the aerosol input in the deposit. The chemical records may, in all probability, provide detailed information regarding the combined effects of soil erosion by agriculture (dust emission) and domestic fires in the regions around the bogs. Iron smelting operations may also have been responsible for the emission of aerosols into the atmosphere. The deposition of lead apparently corresponds to periods of agricultural and industrial expansion and depression. Already during periods of high population densities in prehistoric times some ‘anthropogenic’ aerosols dominated over ‘natural’ fractions. Relatively high lead levels in excavated prehistoric bones from agricultural societies may be explained by an increased uptake of airborne lead (in soil dust and smoke) via the lungs. Geochemical analysis can provide a more complete historical/prehistorical perspective of anthropogenic influence, especially in combination with palynological records.